| 摘要 |
PROBLEM TO BE SOLVED: To increase a mounting speed of an electronic part, and to prevent a free fall of a nozzle even at abnormal time being difficult to position/control a VCM by supplying a constant current quantity preset to the VCM for a constant time at abnormal time being difficult to position the VCM. SOLUTION: When a disconnection detecting circuit 14 detects disconnection of a magnescale 3, the main control part 11 turns on brake output for preventing a freel fall of a nozzle to simultaneously read out a preset electric current value (d) and an operation timer value (t) for flowing the electric current from a memory so as to be switched to constant current control from positioning control by the mode switching part 15. Thus, an electric current corresponding to the preset electric current value (d) flows to a VCM 2, and at the same time, a timer is started. At this time, the preset electric current value (d) is set to a value for holding dead weight of a driving mechanism such as a shaft and a magnet of the VCM 2 and a nozzle ancillary to the shaft, and the timer value (t) is set to a value until a brake completes operation. |
